Glow-tube voltage indicator



NOV. 13, 1951 W, C. UNTON GLOW-TUBE VOLTAGE INDICATOR Filed Aug. 15, 1948 WILL/AM C- Ll/VTO/V.

ze zaza 7 25 Patented Nov. 13, 1951 lUlillflTED .STATES PATENT (GFI-ICE I i i "A 4,575,279 Y GEOWJTUBELVOLTAGEmmox'roa William inton, Washington, v aplicadas atleast 13, 194s.' Aseri-ar Necauie Other objects will be inpartaobvious and` in part pointed out hereinafter asthe description continues.

In the accompanying drawings: l Y Fig. 1 is a side elevation of vthe instrumentgembodying the present invention.` Y

Fig. 2 isa vertical sectional view of the saine.

Fig. 3, a horizontal'section taken -on the .line -33 of Fig. 1 in the directionof the arrowpoints. Fig. 4 is.asimilar view takenon the. lined-4 o f Fig. 1 in the directionof thearrow points.

Fig. 5 is a similar View taken on the line tir-570i Figil inthe direction of-y thekr arrow poiyntsv` Fis. 6 is antherherizentel Sectio teken-oaths line B-SofFig. 2-in thedirection of the .arrow Points j Fig. 7 is .a similar view'talen on thelireI-Tof Eig'. 2 in 'the direction" of 'the arrdvv'litsl Fig. Sis' a Dian view'othe core, and

'Figi 9 is' a elan View of` the" fabricated" laiifp .type voltage" indicated prior'Y to' being" ir'iser't'ed within the core ofv the instrument.

L 'The mstr'um'entghere'in comprises aV Vclasiigl formed" of a cylindrical tube lof' heavy `bre"with its opposite ends openedl andinth'e walrof'tliis tubei-is punchedaf row of i three"opening-sA 2." A nameplate 3 preferably" made "from` plastic materials'partly 'encircling' the louter walli'of` the tube; and is attached' theretoiby means fof 'the driveV screwsfl Thisffname' plate' has-formed therein-a row of't three openings-which register -withi theope'riin'gs 2i df the' casing I" andadja'cent the-uppermost openings -the-nameplate haslthereon? I lit-i215, a'dj acehtf the intermediate dlderiings 1220-24 01 andthe -lowermostopenings4413-6 00.

A core 51 ini the? `fcrrrnoie al cylindrical: rcel.E of

for the. tube i .has-1an exteriorf'diameter the: saine ings; a wedged t will` be effected therebetween. One.- end.v of this coref has formed' Athereini'azlonigitudihally extendingrecess Ii.V and inth'enouter fend of Athe latter .isdriven .a milledzcontactholder 'I .through which extends contact...pin .8". :A ,tighteningscrew cap 9 is connectedtotheholder 1 inorde-r to lgrip the pinor retaining the latter Vinzvarious., extended positions fromithecore. The opposite or. lower end of -thecorezhas-.aflrkshaped .slot IDH-formedtherein through `which extends a exible wire coated conductor. II. @ne endV of this conductoriszknotted .as atAIiZzand 'when` theY `latter. isfsjeatedv within-the enlarged horizontal section'. ofY .the Lf-shaped slot:- the.. con*- 'ductorwill be preventedirompbeing ,drawnirom the vertical section of the. slot; This'cformse a connection between thercore and conductorwithoutan-y separable fasteningelements; This`,.wire conductor II may be of any .desired lengthfbut itsl oppoiste end extends within thetubezsha-ped handle I2. This handle I2 is cut from: a single cylindrical tube of plastic material having its opposite ends opened and within the opened end opposite to that through which the conductor II extendsis a contact holder I3. This contact holder' I3' is of the same construction l.and design that of the contact holder? and has adjlistably extending therethrough another contact' pin I4'. A soldered connection I5'is eiectec between the contact holder I3 and the conductor `I I. Y

The visibleindicator as employed? in't'l'iisinstrument is'of a network construction, as isbefst shownl in Fig. 9 of the drawings and consists-df three'mi'niature neon glow lamps A, `i3 and' C. Each lamp comprises'a glass-bulb having sealed therein two spaced eleetrod'esland from'ea'ch electrode extends the lead wires I'I and Ij The leadwireV I7 of the lamp A' isV electrieallycbnnected as at I9 tov al lead wire'iiil and-the lead wire I8 thereof hasv included therein? a con-'vent'ionalcarbon stickresistor 2I'lrof the"va1ue"^0f 150,000 ohms and is connected as' at 22 to'al'ead Wire 23. The leadv wire I of thelampfBf'is corinected inseries -with a resistor 24 of thel value of `100,000 vohms to the wire 20 as atV landlthe other'lead wire I1 is connected asy at 255th a conductor 25. rIhis conductor 2S has varranged in seriesv therewithV and the vconnec'tidnA 22f ofi the conductor 23 two resistors, one indicatedl asat 21 being of the value of 150,000`ohmsand1fthe other 281of-the value of 50,000 ohms. A resistor 2910i the value of 100,000 ohms has one leadfwfire vconnected-fas aty and" its opposite leadvwire and has arranged therein a resistor 3| of the value of 50,000 ohms. The other lead wire I1 of the lamp C is connected as at 32 to the wire 26 between the resistors 21 and 28.

These miniature neon glow lamps have a striking or breakdown potential of between 50 and 90 volts and in selecting lamps for these positions in the network, it is necessary to separate lamp having the lowest breakdown potential for the lamp A2 After the lamps have been selected they are cured by placing them on a line of 110 volts for about twenty-four hours whereby they will maintain these selected starting potentials. In other words lamps A are selectedvas having Ya breakdown potential of between 50 and 60 volts, lamps B of between 60 and 70 volts and lamps C of about 90 volts. The carbon resistors should have a plus or minus tolerance of not more than of their rated ohmage. The three resistors 2I, 24 and 3l are current limiting resistors, one for each lamp A, B and C respectively whereas, the resistors 21, 28 and 29 are in a voltage divider arrangement so that the lamp C will strike on circuits of 440 volts or above only, lamp B will strike on circuits of 220 volts or above and lamp A will strike on circuits of 110 volts or above. Should these lamps be connected to circuits of 110 to 125 volts, only the lamp A will glow, when applied to circuits of 220 to 240, lamps A and B will glow and when applied to circuits of 440 to 600 volts all three lamps A, B and C will glow.

After fabricating the network of lamps, resistors and wires as show in Fig. 9 of the drawings the same are pressed within recesses formed in the outer periphery of the core 5. The recess 32 33 and 34 of this core receive the lamps A, B, and C respectively. The resistor 2I and 3I are seated Within the recesses 35 and 36 respectively and the resistors 24, 29, 21 and 28 are seated in the recesses 31, 38, 39 and 40 respectively. The wires I1 and I8 are seated within the groove 4I of the core. The wire I8 of the lamp B is seated Within the groove 42 and its wire I1 extends through the groove 43. The wire I8 of the lamp C is seated within the groove 44 and its wire I1 passes through the groove 45. The transverse section of the wire 26 is seated within the groove 46 of the core. After the lamps, resistors and Wires therefore are pressed within and seated in their respective grooves or recesses, the outer end of the wire 23 is inserted through a laterally extending opening 41 of the core 5 wherein it will have electrical contact with the holder 1. The outer end of the wire 20 extends through the slot 48 and is electrically connected to the knotted end of the conductor II. The core or plug 5 is then inserted through the opened lower end of the casing I and forced therein until the electrodes I6 of the lamp A register with the openings having the markings |I0-I25 adjacent thereto. The electrode of the lamp B will then register with the openings having the markings 22B-240 adjacent thereto and the electrodes of the lamp C will register with the openings having the markings 440-690 adjacent thereto.

In use and operation of this instrument, one may hold the casing in one hand and apply the contact pin 8 to one conductor of an electrical circuit, the voltage of which is to be visibly indicated. The handle I2 is grasped in the other handY and its contact pin 8 applied to the other conductor of the electrical circuit. `Should only one electrode of each lamp appear to glow through `the openings 2 of the casing, it will openings formed therein,

indicate that the electrical circuit is of direct current and if both electrodes glow it will indicate that the electrical circuit is of alternating current. If only lamp A glows it will indicate an electrical circuit of between and 125 volts. Should lamps A and B glow, it will indicate an electrical circuit of between 220 and 240 volts and if all three lamps A B and C glow, it will indicate an electrical circuit of between 440 and 600 volts.

The tubes I and I2 of insulation material have relatively thick walls as a safety measure and the core 5 is removably inserted within the tube I so that access may be gained to the electrical connections therein should they become broken. The thick walls of the tube I help one to more readily see the lamps through the openings 2 and determine if one or both electrodes of the lamps appear to be glowing.

I claim:

l. A voltage indicator comprising in combination a tubular casing formed of one piece of insulating material and having its opposed ends opened, said casing having a row of light emitting a cylindrical core formed of one piece of insulating material and insertable through either opened end oi' said casing, said core being of the same length as that or' said casing and having recesses i'orined Within the outer periphery thereof, lamp indicators seated within the recesses of said core, a series of resistors and wires electrically connected to said lamp indicators and seated within other recesses formed in said core, said core having an exterior diameter substantially the same as that of the interior diameter of said casing whereby said casing will contact and retain the said lamp indicators and said series of resistors and wires within the recesses or' said core and permit the light rays iroin the lamp indicators to emit through the row or" openings therein, contact terminais connected to the opposite ends of said core and electrically connected to the Wires seated Within the recesses of said core. and said contact f terminals extending from the opened ends of said casing. y

2. A voltage indicator comprising in combination a tubular casing having its opposite ends opened, a removable cylindrical core formed from one solid piece of insulating material of a length the same as that of said casing, the exterior diameter of said core being the same as that of the interior diameter or said casing whereby said core may be inserted within the casing through one of the opened ends thereof, lamp indicators seated Within said core whereby light rays therefrom may emit through openings formed within said casing, said core having a longitudinally extending recess formed therein, an adjustable contact terminal seated within said recess and extending from one end of said casing, said core having a slot formed within the opposite end thereof, a flexible conductor having one end secured within the slot of said core and extending from the opposite end of said casing, means for electrically connected said lamp indicators to said adjustable contact terminal and said flexible conductor. and a contact terminal connected to the opposite end of said exible conductor.

3. A voltage indicator comprising in combination a holder, said holder being formed from a single unitary piece of cylindrical insulating material having its opposed ends opened, a removablejtray insertable through the opposedopened 2,575,279 Y 5 6 ends of said holder, said tray being formed from REFERENCES CITED a, single piece of cylindrical insulating material The f u ng ef and of substantially the same length as that of me of is galt-215;: erens are of record m the said holder for closing the opposed ends thereof when insertable therein, a visible indicating net- 5 UNITED STATES PATENTS work seated within said tray, said visible indicat- Number Name Date ing network contacting said holder whereby the 1,650,779 Williams Nov. 29, 1927 latter will retain'the same within said tray and 1,744,840 Strieby et al Jan. 28, 1930 said holder having openings therein whereby said 2,094,645 Foulke Oct. 5, 1937 indicating means may be visible exteriorly there- 10 2,163,676 Gizzarelli June 27, 1939 of. 2,249,153 Martin July 15, 1941 WILLIAM C. LINTON. 2,450,153 Moore Sept. 28, 1948 

